Some pyrimidine ammonia compounds with good biological activity were known in prior art. The following compound (K1) with insecticidal and fungicidal activity was reported in U.S. Pat. No. 3,962,442:

The following compound (K2) with fungicidal activity was reported in U.S. Pat. No. 5,075,316:

Although many patents were reported, it's still needed to continue discovering and developing novel fungicides to control harmful diseases in the agrarian, civil and zoo-technical field. The compounds disclosed in above patents were some similar to that in this invention, but there are some obvious differences in structure.